RPS was appointed by East Ayrshire Council in Scotland to undertake the detailed design of a flood alleviation scheme for the town of New Cumnock which had been badly affected by flooding in 2014 and 2015.
The scheme mainly consists of hard defences constructed along the banks of the river through the town; over 2km of earthen embankment and reinforced concrete flood wall have been designed to provide flood protection to the town. Other in-channel works include canalised sections of watercourse to improve the hydraulic capacity, bank erosion protection and engineered spillways.
700m of ‘green’ bank protection has been designed along the Afton Water in consultation with local landowners. The design of these bank protection measures have been tailored to the individual requirements of the river reach in question. In places this includes reinforcement of the slope with geogrid and geotextile technologies, toe protection in the form of wooden stakes and brashwood, and placing of boulders.
At one location along one of the smaller watercourses, an engineered flood spill has been designed whereby existing bank levels are reduced and a spillway over a bank reinforced with geotextiles to allow flooding of a disused railway cutting.
Other services provided to East Ayrshire Council to support the river engineering for the scheme included CDM (health and safety duties), environmental and ecological screening and procurement of various ecological and habitat surveys. RPS obtained a number of Controlled Activities Regulations licences from SEPA to cover a range of activities including channel modification, sediment management and bank modification across the affected watercourses to allow for the proposed works.